Process for producing a tolyl carbinol



Patented May 19 1936 V UNITED STATES PATENT OFFICE amsu" raoonss roa raonncmo a 'romr.

cmmor.

William-J. Amend.

E. I. du Pont do Ncmours & lton,

Del, assign:- to Company, Wil- DeL, a ain-persuade! Delaware No Drawlng. application June 29, 1934,-

Serial No. 133,124

19 Claims. (Cl. 260-153) This invention relates to processes for the The hydrogenation of aldehydes as a class is not new, and there are numerous disclosures covering the use of many types oi, catalysts.

For example, the hydrogenation of benz aldehyde under conditions similar to those of the present invention has been thoroughly disclosed. Likewise numerous aldehydes o1 both the aliphatic and aromatic series have been hydrogenated with platinum catalysts. It has now been discovered that toluic aldehyde may be catalytically hydrogenated to the corresponding tolyl carbinols, especially when using a base metal catalyst.

It is an object of this invention to produce tolyl carbinols from toluic aldehydes by means of catalytic hydrogenation. It is a further object of the invention to carry out these reactions at relatively low temperatures and at pressures above atmospheric in the presence of highly e1- ficient base metal catalysts.

Investigation of the existing processes for the hydrogenation of aldehydes has led tov the discovery that the hydrogenation of toluic aldehydes to tolyl carbinols may be accomplished successfully in the presence of base metal cata lysts at relatively low temperatures and elevated pressures. The following examples set forth preferred embodiments of the invention.

' Example I A charge consisting of 200 g. of p-toluic aldehyde and 20 g. of reduced nickel-on-kieselguhr catalyst was placed in a shaking autoclave and agitated for three hours at -100 C. and 2,000 7 Example II An autoclave equipped for agitation was charged with 200 g. of p-toluic aldehyde and 20 g. of copper carbonate-on-kieselguhr' catalyst. Agitation was maintained temperature of 135 C. to 150 C. and a hydrogen pressure of 2,000 lbs. per sq. in. The reaction products were dissolved in ethyl alcohol and the catalyst removed by filtration. The crystals 01' for 1.5 hours at a hydes for the production p-tolyl carbinol recovered by crystallization amounted to 133g. or 66% of theory.

Example III Two hundred grams of p-toluic aldehyde and 5 15 g. oi. nickel catalyst prepared by digesting a finely powdered 50% nickel-aluminum alloy with sodium hydroxide were agitated in an autoclave for 4 hours at a temperature 01' 45 to 60 C. and a hydrogen pressure of 1,400 to 2,100 lbs. per 1 sq. in. Separation of the reaction products as described in Example II gave a yield of 128 g. of p-tolyl carbinol which was 64% 01' theory.

Example IV A solution of 3,545 g. of p-toluic aldehyde in 500 g. or ethyl alcohol together with 290 g. of copper chromite-on kieselguhr catalyst was charged into an autoclave and agitated for 2.5 hours at a temperature of C. to C. and 20 a hydrogen pressure 01' 1,200 to 2,200 lbs. per sq. in. The catalyst was removed by filtration and there was obtained by crystallization, 2,404 g. (68%) 01' p-tolyl carbinol crystals.

' Example V A charge consisting of 150 g. or p-toluic aldehyde dissolved in 50 g .oi water, and 12 g. of nickel .catalyst prepared by digesting a finely powdered 50%-nickel-aluminum. alloy with sodium hydroxide was agitated in an autoclave for v 1.7 hours at a temperature of 45 to 55 C. and a hydrogen pressure of 1,200 to 2,200 lbs. per sq. in. From the reaction products, there was obtained 93 g. (62%) of p-tolyl carbinol crystals.

Ortho-toluic aldehyde may be used in place of p-toluic aldehyde under the conditions 01 this example to obtain o-tolyl carbinol.

Example VI Two hundred grams oi! dihydro-p-toluic aide.- hyde dissolved in 100 g. of ethyl alcohol, and 10 g. of nickel catalyst prepared by digesting a finely powdered 50% nickel-aluminum alloy with sodium hydroxide was charged into an autoclave and agitated for 4.5 hours at a temperature a hydrogen pressure of in. On separating the was obtained 50 g. 01 g. of hexahydro-p-toiyl' carbinol.

The processes or the present invention are applicable to ortho-, meta-, and para-toluic aldeoi the corresponding 55 p-tolyl carbinol and 100 tolyl carbinols.

on inert materials such as kieselguhr, pumice.

silica gel, etc. A preferred nickel catalyst is prepared by digesting a nickel-aluminum alloy with sodium hydroxide according to the Raney meth- 0d as described in U. 8. Patent 1,628,190- Another preferred catalyst consists of freshly reduced nickel supported on kieselguhr and which has been protected after reduction from undue exposure to the air. i

.Temperature is an important factor in the success of the processes of this invention. Operable temperatures range from C. to 200 C. However, the optimum temperature for a given hydrogenation will depend uponthe catalyst employed. Forjexample, when employing a nickel catalyst the preferred temperature range is be 'termi tween 40 C. and 80 C., whereas copper catalysts such'as copper chromite or copper carbonate are most eiiicient in the temperature range of 125 C. to 175 C.

Pressures above atmospheric are required for the processes herein described. Pressures in the range of 1,000 to 3,000 lbs. per sq. in. are preferred, but a wider range of pressure may be employed, say from 25 lbs. per sq. in. to an upper limit deed only by the-strength of the. reaction vessel.

As, indicated inthe examples, the toluic aldeh'ydes may be hydrogenated alone or in the presence of solvents'such as water; alcohol, hydrocarbons,esters,.etc. v

The processes of the present invention provide a new, practical, and economical, method for ob-' taining tolyl carbinols -fromitoluic aldehydes.

The products are of pleasant odors and may be employed in the manufacture of compounds used as perfumes. As many apparently and widely different embodiments of this invention may be made without I departing from the spirit and scope thereof, it is to be understood thatI do not limit myself to the specific embodiments thereof except, as defined in the appended claims. v I r I claim:

1. A process of hydrogenating a toluic aldehyde Y having the aldehyde radical directly attached to the ring which comprises contacting said toluic aldehyde and hydrogen in the presence of a catalyst at a temperature of about 25 C. to 200 C. and at a superatmospheric pressure.

2. .A process of hydrogenating a toluic aldehyde having the aldehyde radical directly attached to the ring to form a corresponding tolyl carbinol which comprises contacting said toluic aldehyde and hydrogen in the presence of a hydrogenation catalyst at a temperature oi about 25 C. to 200 C. and at a superatmospheric pressure.

3. A process of hydrogenating a toluic aldehyde having the aldehyde radical directly attached to the ring to form a corresponding tolyl carbinol which comprises contacting said toluic aldehyde 25 C. to 200 C. and at a superatmospheric pressure.

4. A process of a toluic aldehyde having the aldehyderadicaldirectly attached to therlngtoformacorresponding tolyl carbinol which comprises contacting said toluic aldehyde andhvdrogeninthepresenceofacatalystcomprising copper chromite at a temperature of about 25 C. to 200 C. and at a superatmospheric pressure mom to form a tolyl carbinol which comprisescont'actingsaid toluic aldehyde and hydrogen in the presence ofa hydro enation catalyst at. a temperature of 25 C. to 200 C. and at a superatmospheric pressure.

6. A. process of hydrogenating a toluic aldehyde having the alddiyde radicaldircctiy at-v tachedtotheringtoformacorrespondingtolyl carbinol which comprises contacting said toluic aldehyde and hydrogen in the presence of a nickel catalyst at a temperature of 40' C. to .80 C. and at a mperatmosphericpressure:

7. A-process of a toluic aldehyde having the aldehyde radical directly attachedto theringtoformacotolyl carbinol which comprises contactingsaidtoluic aldehydeand hydrogen in the presence of a copper containing catalyst at a temperature of C. to C. and at a su pressure.

8.Aprocersof.atoluicaide- 3000 lbsJper 10. A process of a toluic aldehyde having the aldehyde radical directly at- 5. 'A process of hvdrogenating a toluic aldehyde havingthe aldehyde radical directly attached to tached to the ringto form a corresponding tolyl carbinol which comprises contacting said toluic aldehydeandhydrogeninthcpresenceofahydrogenlttion catalyst at a temperature of about toluic aldehyde and hydrogen at atemperatureof from 25 to200 C. and atsuperatmospheric pressure in the presence of a hydrogenation catalyst and an inert solvent.

12. A process of p-toluic aldehyde to form p-tolyl carbinol which comprises contacting p-toluic aldehyde and hydrogen in the presence of a base metal hydrogenation catalyst at a temperature from about 25' C. to 200C. and at a superatmospheric pressure. 1

13. A process of hydrcgenating p-toluic aldehyde to form p-tolyl carbinol which comprises contacting .p-toluic aldehyde and hydrogen in the presence of a comprising copper chromite at a temperature from about 25 C. to 200 C. and at a superatmospheric pressure.

14. A process 01' hydrogenating p-toluic aldehyde to form p-tolyl carbinol which comprises contacting p-toluic aldehyde and hydrogen in the presence of a hydrogenation catalyst at a temperature of 25 C. to 200 C. and at a superatmospheric pressure.

15. A process of hydrogenating p-toluic aldehyde to form p-tolyl carbinol which comprises contacting p-toluic aldehyde and hydrogen in the presence of a nickel catalyst at a temperature 01 C. to C. and at a superatmospheric pressure.

16. A process of hydrogenating p-toluic aldehyde to form p-tolyl carbinoi which comprises contacting p-toluic aldehyde and hydrogen in the presence of a copper containing catalyst at a temperature of C. to 175 C. and at a superatmospheric pressure.

17. A process of hydrogenating p-toluic aldehyde to form p-tolyl carbinol which comprises 3 contacting p-toluic aldehyde and hydrogen in the presence of a base metal hydrogenating catamixture consisting oi. p-tolulc aldehyde in ethyl alcohol and hydrogen while in contact with a catalyst consisting of copper chromite-on-kieselguhr, maintaining the reactants at a temperature of C. to C. and at a hydrogen pressure of 1200 to 2200 lbs. per square inch for two and one-hall hours.

WILLIAM J. AMEND. 

